Questions & Answers of Networks

Question No. 19

Consider a two-port network with the transmission matrix: T=ABCD. If the network is reciprocal, then

Question No. 43

An AC voltage source V = 10 sin(t) volts is applied to the following network. Assume that R1 = 3 kΩ, R2 = 6 kΩ and R3 = 9 kΩ, and that the diode is ideal.

RMS current Irms (in mA) through the diode is ________

Question No. 44

In the circuit shown in the figure, the maximum power (in watt) delivered to the resistor R is __________

 

Question No. 116

In the circuit shown below,VS is a constant voltage source and IL is a constant current load.

The value of IL that maximizes the power absorbed by the constant current load is

Question No. 117

The switch has been in position 1 for a long time and abruptly changes to position 2 at t=0.

If time t is in seconds, the capacitor voltage VC (in volts) for t > 0  is given by

Question No. 118

The figure shows an RLC circuit with a sinusoidal current source.

At resonance, the ratio IL/IR, i.e., the ratio of the magnitudes of the inductor current phasor and the resistor current phasor, is ________

Question No. 119

The z-parameter matrix for the two-port network shown is

 2jωjωjω3+2jω,

where the entries are in Ω. Suppose Zbjω = Rb+jω

Then the value of Rb (in Ω) equals ________

Question No. 140

In the given circuit, each resistor has a value equal to 1 Ω.

What is the equivalent resistance across the terminals a and b ?

Question No. 141

In the circuit shown in the figure, the magnitude of the current (in amperes) through R2 is ___

 

Question No. 219

In the RLC circuit shown in the figure, the input voltage is given by

               vi(t) = 2 cos(200t) + 4sin(500t)

The output voltage v0(t) is

 

Question No. 242

Assume that the circuit in the figure has reached the steady state before time t=0 when the 3 Ω resistor suddenly burns out, resulting in an open circuit. The current i(t) (in ampere) at t=0+ is __________

 

Question No. 243

In the figure shown, the current i (in ampere) is __________

 

Question No. 244

The z-parameter matrix $\begin{bmatrix}z_{11}&z_{12}\\z_{21}&z_{22}\end{bmatrix}$ for the two-port network shown is

 

Question No. 16

In the circuit shown, at resonance, the amplitude of the sinusoidal voltage (in Volts) across the capacitor is ______ .

Question No. 17

In the network shown in the figure, all resistors are identical with R = 300 Ω. The resistance Rab (in Ω) of the network is __________.

Question No. 18

In the given circuit, the values of V1 and V2 respectively are

Question No. 40

The damping ratio of a series RLC circuit can be expressed as

Question No. 42

In the given circuit, the maximum power (in Watts) that can be transferred to the load RL is ____.

Question No. 116

The voltage (VC) across the capacitor (in Volts) in the network shown is _______

Question No. 117

In the circuit shown, the average value of the voltage Vab (in Volts) in steady state condition is _______.

Question No. 118

The 2-port adminittance matrix of the circuit shown is given by

Question No. 140

An LC tank circuit consists of an ideal capacitor C connected in parallel with a coil of inductance L having an internal resistance R. The resonant frequency of the tank circuit is

Question No. 141

In the circuit shown, the Norton equivalent resistance (in Ω) across terminals a-b is ___________.

Question No. 216

For the circuit shown in the figure, the Thevenin equivalent voltage (in Volts) across terminals a-b is _____.

Question No. 217

In the circuit shown, the voltage Vx (in Volts) is ____.

Question No. 218

At very high frequencies, the peak output voltage Vo (in Volts) is_____.

Question No. 240

In the circuit shown, the current I flowing through the 50 Ω resistor will be zero if the value of capacitor C (in μF) is _______.

Question No. 241

The ABCD parameters of the following 2-port network are

Question No. 16

For maximum power transfer between two cascaded sections of an electrical network, the relationship between the output impedance Z1 of the first section to the input impedance Z2 of the second section is

Question No. 17

Consider the configuration shown in the figure which is a portion of a larger electrical network

For R=1 Ω and currents i1=2 A,i4=−1 A,i5= −4 A, which one of the following is TRUE?

Question No. 40

A Y-network has resistances of 10Ω each in two of its arms, while the third arm has a resistance of 11 Ω. In the equivalent Δ-network, the lowest value (in Ω.) among the three resistances is ________

Question No. 41

A 230 V rms source supplies power to two loads connected in parallel. The first load draws 10 kW at 0.8 leading power factor and the second one draws 10 kVA at 0.8 lagging power factor. The complex power delivered by the source is

Question No. 42

A periodic variable x is shown in the figure as a function of time. The root-mean-square (rms) value of x is _________.

Question No. 43

In the circuit shown in the figure, the value of capacitor C (in mF) needed to have critically damped response i(t) is________.

Question No. 116

Norton’s theorem states that a complex network connected to a load can be replaced with an equivalent impedance

Question No. 117

In the figure shown, the ideal switch has been open for a long time. If it is closed at t=0, then the magnitude of the current (in mA) through the 4 kΩ resistor at t= 0+ is _______.

Question No. 141

In the h-parameter model of the 2-port network given in the figure shown, the value of h22 (in S) is ______ .

Question No. 142

In the figure shown, the capacitor is initially uncharged. Which one of the following expressions describes the current I(t) (in mA) for t >0?

Question No. 216

A series RC circuit is connected to a DC voltage source at time t = 0. The relation between the source voltage VS, the resistance R, the capacitance C, and the current i(t) is given below:

Vs=Rit+1C0tiu.

Which one of the following represents the current i(t)?

Question No. 217

In the figure shown, the value of the current I (in Amperes) is __________.

Question No. 240

Consider the building block called ‘Network N’ shown in the figure.
Let C = 100 μF and R = 10 kΩ.

Two such blocks are connected in cascade, as shown in the figure.

The transfer function V3sV1s of the cascaded network is

Question No. 241

In the circuit shown in the figure, the value of node voltage V2 is

Question No. 242

In the circuit shown in the figure, the angular frequency ω (in rad/s), at which the Norton equivalent impedance as seen from terminals b-b′ is purely resistive, is _________.

Question No. 243

For the Y-network shown in the figure, the value of R1 (in Ω) in the equivalent Δ-network is ____.

Question No. 316

The circuit shown in the figure represents a

Question No. 340

The steady state output of the circuit shown in the figure is given by

$y\left(t\right)=A\left(\omega\right)\sin\left(\omega t+\phi\left(\omega\right)\right).$If the amplitude Aω=0.25 , then the frequency ω is

Question No. 341

In the circuit shown in the figure, the value of v0(t) (in Volts) for t→∞ is ______.

Question No. 343

For the two-port network shown in the figure, the impedance (Z) matrix (in Ω) is

Question No. 11

Consider a delta connection of resistors and its equivalent star connection as shown below. If all elements of the delta connection are scaled by a factor k, k> 0, the elements of the corresponding star equivalent will be scaled by a factor of

Question No. 22

The transfer function V2(s)V1(s) of the circuit shown below is

Question No. 23

A source v s (t) = V c o s 100 π t has an internal impedance of (4+j3)Ω . If a purely resistive load connected to this source has to extract the maximum power out of the source, its value in Ω  should be

Question No. 28

In the circuit shown below, if the source voltage VS = 10053.13° V then the Thevenin’s equivalent voltage in Volts as seen by the load resistance RL is

Question No. 31

The following arrangement consists of an ideal transformer and an attenuator which attenuates by a factor of 0.8. An ac voltage VWX1 = 100V is applied across WX to get an open circuit voltage VYZ1  across YZ. Next, an ac voltage VYZ2 =100V is applied across YZ to get an open circuit voltage VWX2 across WX. Then, VYZ1 / VWX1, VWX2 / VYZ2 are respectively,

Question No. 32

Two magnetically uncoupled inductive coils have Q factors q1 and q2 at the chosen operating frequency. Their respective resistances are R1 and R2. When connected in series, their effective Q factor at the same operating frequency is

Question No. 44

Three capacitors C1, C2 and C3 whose values are 10μF, 5μF, and 2μF respectively, have breakdown voltages of 10V, 5V, and 2V respectively. For the interconnection shown below, the maximum safe voltage in Volts that can be applied across the combination, and the corresponding total charge in μC stored in the effective capacitance across the terminals are respectively,

Question No. 50

Consider the following figure

The current IS in Amps in the voltage source, and voltage VS in Volts across the current source respectively, are

Question No. 51

Consider the following figure

The current in the 1 Ω resistor in Amps is

Question No. 9

In the following figure, C1 and C2 are ideal capacitors. C1 has been charged to 12 V before the ideal switch S is closed at t = 0. The current i(t) for all t is

Question No. 10

The average power delivered to an impedance (4-j3)Ω by a current 5cos100πt+100A is

Question No. 21

The impedance looking into nodes 1 and 2 in the given circuit is

Question No. 22

In the circuit shown below, the current through the inductor is

Question No. 33

Assuming both the voltage sources are in phase, the value of R for which maximum power is transferred from circuit A to circuit B is

Question No. 45

If VA-VB=6V, then VC-VD is

Question No. 48

With 10 V dc connected at port A in the linear nonreciprocal two-port network shown below, the following were observed:

(i) 1Ω connected at port B draws a current of 3 A
(ii) 2.5Ω connected at port B draws a current of 2 A

With 10 V dc connected at port A, the current drawn by 7Ω connected at port B is

Question No. 49

With 10 V dc connected at port A in the linear nonreciprocal two-port network shown below, the following were observed:

(i) 1Ω connected at port B draws a current of 3 A
(ii) 2.5Ω connected at port B draws a current of 2 A

For the same network, with 6 V dc connected at port A, 1Ω connected at port B draws 7/3 A. If 8 V dc is connected to port A, the open circuit voltage at port B is

Question No. 10

In the circuit shown below, the Norton equivalent current in amperes with respect to the terminals P and Q is

Question No. 11

In the circuit shown below, the value of RL such that the power transferred to RL is maximum is

Question No. 23

The circuit shown below is driven by a sinusoidal input vi = Vp cos (t /RC). The steady state output vo is

Question No. 33

In the circuit shown below, the network N is described by the following Y matrix:

Y=0.1S-0.01S0.01S0.1S. The voltage gain V2V1 is

Question No. 34

In the circuit shown below, the initial charge on the capacitor is 2.5 mC, with the voltage polarity as indicated. The switch is closed at time t=0. The current i(t) at a time t after the switch is closed is

Question No. 46

In the circuit shown below, the current I is equal to

Question No. 4

For the two-port network shown below, the short-circuit admittance parameter matrix is

Question No. 5

For parallel RLC circuit, which one of the following statements is NOT correct?

Question No. 22

If the scattering matrix [S] of a two port network is

s=0.20o0.990o0.990o0.190o

then the network is  

Question No. 32

In the circuit shown, the switch S is open for a long time and is closed at t=0. The current i(t) for t≥0+ is

Question No. 33

The current I in the circuit shown is

Question No. 34

In the circuit shown, the power supplied by the voltage source is

Question No. 14

In the interconnection of ideal sources shown in the figure, it is known that the 60 V source is absorbing power

Which of the following can be the value of the current source I ?

Question No. 17

If the transfer function of the following network is V0sVis=12+sCR,

The value of the load resistance RL is

Question No. 27

An AC source of RMS voltage 20V with internal impedance Zs=(1+2j)Ω feeds a load of impedance ZL=(7+4j)Ω in the figure below. The reactive power consumed by the load is

Question No. 29

In the circuit shown, what value of RL maximizes the power delivered to RL?

Question No. 30

The time domain behavior of an RL circuit is represented by

Ldidt+Ri=Vo1+Be-Rt/Lsintut.

For an initial current of i0=VoR, the steady state value of the  current is given by

Question No. 7

In the following graph, the number of trees (P) and the number of cut-sets (Q) are